Lathe



C. OVFRGAARD.

LATHE.

APPLICATION FILED NOV. 28, I919.

Patented Jan. 27, 1920.

3 SHEETSSHEET I.

C. OVERGAARD.

LATHE.

APPLICATION FILED NOV. 28, 1919.

Patented Jan. 27, 1920.

3 SHEETSSHEET 2- C. OVERGAARD.

LATHE.

APPLICATIONJILED NOV. 28. 1919.

1,328,962, Patented Jan. 27, 1920.

ESHEETS-SHEET 3- fnvewzn':

[Zr-Lil e ave 46 w UNITED STATES CHRISTEN OVEB-GAARD, 0F SKOVSEOVED, NEAR COPENHAGEN, DENMARK.

LATHE.

Application filed November 28, 1919.

To all whom it mm concern:

Be it known that I, CHRisTnN OVERGAARD, director, subject of the Kingdom of Denmark, residing at Nr 9, Syibakken, Skovshoved, near Copenhagen, Denmark. have invented certain new and useful Improvements in Lathes, of which the following is a specification.

On the ordinary lathes there are provided, as it is known, a pair of ordinary horizontal guiding-bars supporting the head stock and tail stock as well as the steady rest and tool-rest. In the most recent constructions of special latches, however, the tool-rest has frequently been disposed in such a manner that it is supported on only one of the bed-guides, whereon it hangs, so to speak, it being further fitted with a vertical downwardly directed member resting against the side of the guide-bar, where it has a plane sliding surface resting against and movable along a vertical guide-surface.

In these known constructions of lathes, the head and tail stocks as well as the steady rest are supported, as mentioned above, by both of the two bed-guides, so that the axis of the piece of work will be located in the central vertical plane between the guides. The work fixed in this manner must be able to rotate without touching the guides, and the size of the pieces of work which may be turned on a lathe is therefore limited, inasmuch as their radii must not exceed the shortest distance from the axis of the spindle down to the horizontal portion of the tool-rest, which is placed as a bridge across the guide-bars.

In order to remedy this drawback, the bed has been offset or dished, in some lathes, for a distance near the head stock whereby space is provided here in which shorter pieces of work of larger diameter can rotate. advantages but is subject to the drawback that the absence of the guides on the central piece prevents the tool-rest from being moved clear up to the head stock.

In opposition to the above mentioned known lathe constructions, the present invention relates to a lathe with only one guide-bar supporting the head stock and tail stock as well as the steady rest and the tool-rest. According to the invention the said single guide-bar, in order to provide room for the largest possible pieces of work,

Specification of Letters Patent.

This construction may offer certain' Patented Jan. 27, 1920.

Serial No. 341,231.

is displaced sidewise relatively to a vertical plane through the spindle-shaft. and the guide-bar supports the tool-rest sliding on one side thereof, while the steady rest and tail stock may slide along the other side of the guide-bar.

The toolrest is ordinarily arranged in the above mentioned known manner, so that it is supported by the top-portion of the bed-guide and, more or less, hangs out over the bed, against the side of which it rests by means of a sliding surface or the like on a downwardly directed portion of the toolrest. I

On the drawing there is represented one manner of constructing the invention.

Figure 1 shows, in front elevation, a small lathe constructed according to the invention.

Figs. 2 and 8 show the same in cross-section which may be supposed to be located at the point where the lathe is broken on Fig. 1.

Fig. 2 shows the lathe without the steady rest.

Fig. 3 the same with the steady-rest.

The head stock is marked 1 and the tail stock 2, is the tool-rest shown on Figs. 2 and 3 to be hung on the left hand side of the bed 4-; at top and at bottom the toolrest- 3 engages, by means of suitable flanges, the horizontal top portion of the bed from above, and engages from below the bottommost lefthand edge of the bed.

The tool-rest 3 is moved by rotation of the pinion 5, which engages the rack 6 (Figs. 1 to The head and tail stocks and the steady rest 9 may be held to the bed in the manner shown in Figs. 2 and 3, where they are guided on the bed 4 by means of tongues 7 engaging grooves in the bed. The stocks and the steady rest 9 are fixed to the bed by means of bolts 8 or the like.

As it appears from Figs. 2 and 3. it is by locating the single guide-bar of the lathe to one side of a vertical plane through the spindle-axis of the lath, and by placing the head and tail stocks on the less steep side of the guide-bar that the advantage is obtained that there will be ample space between the spindle and the guide-bar, so that work of larger diameter may be turned on the lathe here specified than on the known lathes of similar size.

Furthermore, the distribution of forces on the bed becomes more favorable, as it must be remembered that there is produced, during theturning operation, a downwardly directed pressure acting in such a manner on the bed that tensile stresses will be produced at the lower edge thereof and compressive stresses at top, and as the bed in practically all cases is made of cast iron, the triangular shape will therefore be the most favorable one, as this shape provides maximum strength with the minimum amount of material. A very important advantage is, finally, that the tool-rest may be moved beyond the tail stock as Well as the steady rest, thus enabling any shaft to be turned without having to be reversed in the lathe, whereby some time is saved.

The location of the piece work above one of the inclined sides of the bed involves the advantage that cuttings and the like will not remain on the bed, so that they will not damage the wearing surfaces of the bed and the like, but will slide down along the bed and drop to the ground alongside the lathe. The construction of the lathe renders it practicable to arrange the head stock at least without connection with the bed, 2'. e. as an independent member standing on the floor of the shop. This may be of interest in case of very large lathes, for instance lathes adapted to turn propeller shafts and the like.

I claim- 1. In a lathe, the combination with the head stock and spindle, of a single guide bed having the form of a scalene triangle in cross-section, the apex of such triangle being directed upward and located to one side of a vertical plane passing through the spindle so as to provide a relatively large workspace between the latter and the bed; a tool rest mounted to slide along one of the inclined sides of the bed; and a tail stock and steady rest mounted to slide along the other inclined side of the bed, the tool rest being movable beyond the tail stock and the steady rest.

2. In a lathe, the combination with the head stock and spindle, of a single guide bed having the form of a scalene triangle in cross-section, the apex of such triangle being directed upward and located to one side of a vertical plane passing through the spindle so as to provide a relatively large workspace between the latter and the bed; a tool rest mounted to slide along the steeper of the two inclined sides of the bed; and a tail stock and steady rest mounted to slide along the less steep inclined side of the bed, the tool rest being movable beyond the tail stock and the steady rest.

In testimony whereof I aflix my signature.

CHRISTEN OVERGAARD. 

